


Messy Lairs

by kuro1neko2kun



Category: Mortal Instruments Series - Cassandra Clare, Shadowhunters (TV)
Genre: M/M, Magnus loosing control of his magic, Making a mess, after S1, alec is out
Language: English
Status: Completed
Published: 2016-04-13
Updated: 2016-04-13
Packaged: 2018-06-02 02:52:53
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,088
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6547708
Author URL: https://archiveofourown.org/users/kuro1neko2kun/pseuds/kuro1neko2kun
Summary: <blockquote class="userstuff">
              <p>Magnus may have a little problem controlling himself when he and Alec are getting it on. People are starting to notice how messy his apartment has gotten.</p>
            </blockquote>





	1. Sloppy

**Author's Note:**

> Based on the Tumblr headcanon floating around that Magnus loses control of his magic when he and Alec are having sex.

It's the first time after the failed wedding, and Jace's subsequent disappearance that they're visiting Magnus's loft, and Simon can't help but think that there's something different about it. It looks the same, layout wise, there's still bookcases along the walls and a bright orange arm chair. But there's something…different about it.

As Magnus appears in the doorway to his office, it hits Simon, what's different. The couch used to be blue. It was definitely blue the last time he was looking at it, even if Luke's frame had covered most of it. It was now a deep burgundy colour, and littered with sparkles. Alec appeared in the doorway to another room (maybe the bedroom?) and Simon blinked.

Maybe….naw. Couldn't be that.

-

Isabelle looked around Alec's room in bewilderment, taking in the clothes strewn about the floor, books lying open on the desk, and, even more confusingly, the new mauve curtains across his window. Had he gone on an interior design kick lately without her noticing? She glanced at the bed, and snickered, the bits of glitter clinging to the pillow catching the light.

Ah. 

Maybe it was Magnus that had added a bit of colour to Alec's room, just as he was adding colour to the rest of his life.

Well, Alec was clearly not in his room, so she headed down to the archery range. 

-

Raphael glanced around Magnus's apartment warily, taking in the new art installation on the opposite wall. It looked a little like Magnus had just covered it in glue and then thrown glitter all over it.

"Magnus?" He called into the seemingly empty loft.

"Hang on-oh, just a second." Magnus's voice was breathy, and Raphael pointedly didn't think of why that might be. There was a flash, and suddenly the bookcase along the wall fell over. He pretended that he didn't jump a foot in the air,

"Raphael, to what do I owe the…pleasure?" Magnus appeared from his room looking like he'd just gotten out of bed, hair a mess and shirt only half buttoned, feet bare. 

"I need to see a copy of the contract you drew up for Camille-" Raphael wrinkled his nose at the distinct smell of sex that was wafting from Magnus's direction. "I can come back if you already have company though."

He heard someone in the bedroom moving around, and he aimed a pointed look at the door. Magnus just smirked and waved his hand, the door flying shut behind him.

"No need, I can get you the contract and you can be on your way. No need to see you more than once in a day." He took in the mess on his floor and snapped his fingers with a frown. Raphael smirked as the bookcase reverted to it's usual position with a shimmer of blue fire.

"I don't particularly want to come back, so…" Magnus rolled his eyes and snapped his fingers again, a paper appearing on the table. 

"There you go, you ungrateful youngling." He gestured at it lazily. Raphael picked it up to examine it's contents before nodding, tucking it into the inside pocket on his blazer.

"Thanks." He turned to leave, hearing the squeak of Magnus's bedsprings just as he entered the elevator, tuning out the low murmur of voices.

-

Clary was the one who finally figured out why Magnus's apartment was getting progressively messier every time they visited. It was an accident, really, that she'd been the one assigned to retrieve Alec from Magnus's apartment for a hunt. Usually that was Isabelle's job, but today Isabelle had been busy in the forensics lab and, considering everyone else's reluctance to even discuss what had happened at the wedding, she was the only one who had a clue where Alec was when a quick search of the Institute didn't turn him up.

She made her way out of the elevator and into Magnus's apartment, taking in the darkness and general quiet of the main room. Maybe they were out? She activated her sight rune with a flick of her stele, moving farther into the apartment. A quiet murmur had her focusing her attention down the hallway, and she walked towards it hesitantly. 

She stifled a gasp when she pushed the door open, wondering if it was too late to go back downstairs and ring the doorbell.

Alec's broad back was visible in the darkness, the dark lines of his runes standing out against his pale skin. A sheet was (luckily) pulled up to his waist, obscuring her view, but she could make out a slighter form below him. The bedsprings creaked and she covered her mouth, hearing the grunts and groans that she hadn't been able to make out from the entryway.

Backing away slowly, Clary tried to make her way back out of the apartment. Her progress was halted by a sudden flare of blue light, and suddenly she, along with everything else in the apartment, was floating, as though gravity had suddenly been turned off. There was another series of loud moans from the bedroom and she realized her hair was starting to cycle through a rainbow of colours.

Green.

The couch was suddenly replaced with an ornate throne.

Blue.

The painting at the end of the wall changed into the Mona Lisa.

Violet.

Everything came crashing down with a shout from the bedroom, including her.

There was a moment of silence, and Clary picked herself up off the ground with a wince, rubbing at her tailbone with one hand. Guess who was definitely not going to enter Magnus's apartment without knocking again.

She made her way to the couch, stepping through the mess of books and papers carefully, pausing by the armchair, now an alarming shade of neon yellow. It clashed with her hair.

There was a muffled groan from the bedroom.

"I should really get back to the Institute." Alec's voice was huskier than usual.

"Already?"

"I've been here all afternoon, someone's bound to wonder where I've gone soon."

"I suppose." There was a deep sigh and a period of silence, and Clary tried very hard not to imagine what was happening.

"Did you see where my shirt went?"

"You don't really _need_ one, darling. You look great without it." 

Another moment of silence.

"Oh, fine. I think I saw it on top of the lamp."

"The lamp? How did it even-?" Alec's voice was incredulous. She could hear Magnus snickering softly.

"You know I can't control it, Alexander. I thought you'd be used to this by now."

"Never." Alec's voice is filled with fondness, and Clary can't help but think wistfully of Jace.

"Well, I suppose I'll escort you to the door." She hears a snap, and scrambles to her feet, tripping over a book in her haste to get out the door.

"What was that?" Alec's voice lost it's playful edge, and Clary winced. Busted.

There was a scuffling sound, and Alec appeared at the end of the hall, peering right at her. 

"Um. Hi?" She waved sheepishly.

"What are you doing here?" Alec's face flushed so bright it practically glowed in the dark. "How long have you been here?"

Magnus appeared behind him, and clapped, the lights all flickering on and revealing her new hairstyle.

"Um."

"Biscuit, I didn't take you for a voyeur." Magnus grinned, gesturing at her hair. "Although purple rather suits you."

" _Magnus_ -" Alec's voice is pained.

"I really didn't mean to, it's just…" Clary waved her hands in front of her. "There was demon activity reported in central park and Izzy was taking care of something else so I ended up having to come get you…we tried to text you…"

Alec pulled his phone out of his pocket and winced.

"Can we-uh… forget this ever happened?" He gestured between them awkwardly.

"Might be a little hard…" She gestured at her hair and winced at the unintended pun while Magnus snickered.

"Here, let me-" Magnus stepped forward, revealing that he was only wearing a dressing robe and slippers, and ran a glowing hand through her hair, returning it to it's natural colour. "There you go, same as before."

"Thanks…" Clary examined a strand of her hair to ascertain that it was the correct colour before gesturing at the door. "We really do have a mission to get to…"

"Right." Alec fumbled with his phone for a moment before stepping forward. "Let's go."

Clary led the way back downstairs, face slightly flushed. Magnus grabbed onto Alec by the belt loops just as he was about to follow her down the stairs.

"Stay safe, Alexander." He leaned up on tiptoes, pressing their lips together. Alec kissed back briefly before pulling away.

"Of course. I'll text you later?"

"I look forward to it." Magnus relinquished him with a sigh, and Alec followed Clary down the stairs and out the door.

She turned back to face Alec as they made their way towards the subway station, 

"I'm really sorry about this-"

"Don't mention it."

"I didn't mean to walk in on you two…"

"No seriously." Alec's blush flared up again. "Don't mention it."


	2. Fires

**Summary for the Chapter:**

> New rules are established

**Notes for the Chapter:**

> This is Cookie's fault.

No one was quite sure to bring it up. But after the fire, it was clear that something had to be done. 

Simon was sent first, because he was a pushover.

-

"Um. Alec. Nice night, huh?"

"Sherman." Alec's face was unimpressed as he looked up from where he was cooking dinner. "What do you want."

"It's Simon, actually." Alec scowled and Simon backtracked hurriedly. "No, that's okay, call me whatever you want."

"What. Do. You. Want." 

Simon had no idea that flipping a pancake could look menacing, but Alec had managed it.

"It's just- we wanted- Magnus-" He stuttered, backing away slowly. "Pleasestopsettingthingsonfirethanks."

Alec was left blinking after him after Simon used his vampire speed to retreat.

-

Clary tried after the second fire, because this really needed to be dealt with. She and Alec had been getting along better recently…right? Plus, Isabelle was busy dealing with the Seelies.

"Alec-"

"A little busy here." Alec released the bar, landing lightly on his feet on the mat. "What is it."

"I just wanted to talk you you about Magnus-"

"I told you not to mention that again." Alec rolled his eyes at her, starting to wrap up his hands for a go at the punching bag.

"No, no, I wasn't going to-" she followed him to the bench, perching on the edge as he tied off one hand. "There's been a lot of fires lately and we just-"

Alec's face was turning red, and Clary sighed.

"Please stop doing that at-"

"Alexander?" Magnus interrupted her, and Clary watched as Alec's face practically lit up when he looked at the warlock. "Are you busy right now?"

"Just getting some training in," Alec didn't even look at Clary. 

"I was just visiting to undo the adjustments I made to the wards and I finished early…" Magnus grinned suggestively.

"Guys…?" Clary wasn't entirely certain they even knew she was there anymore.

"I guess I could take a break…" Alec was grinning crookedly, and she threw up her hands. Someone else could deal with this.

-

Isabelle finally stepped in after they set the roof on fire.

"Alec." She intercepted him just as he was heading back to his room to change for a date. "I need to talk to you."

"What about?" Alec paused in the hall, turning to her curiously.

"You and Magnus need to stop having sex in the Institute."

She watched in fascination as his entire face promptly turned bright red.

"We're not- We haven't- Izzy!" 

"Oh please." She rolled her eyes at him. "It's pretty obvious. The walls in our hallway were _definitely_ not purple last week. And you set fire to the roof this morning."

"We didn't… It wasn't-" Alec sidled down the hallway and she followed persistently. "He can't help it, okay?"

"And that says great things about your skills," Izzy wrinkled her nose a little, "That I definitely didn't need to know. But seriously. Just… try to restrain yourselves when you're here."

"But-"

"I didn't say stop entirely." She smirked. "You can have as much kinky magical sex as you want at his place. Just… not here."

Alec squeaked at her wording and darted into his room, door closing forcefully behind him. She snickered and pulled out her phone to text him.

_Remember, keep it in your pants when you're at home.  
As for what you do at his place… Well, don't do anything I wouldn't do ;)_


End file.
